This is an interesting topic but could fall foul of semantics. Conflict, argument, debate, dissention etc etc.
I think you need first to carefully define your understanding of argument, because I would suggest that your definition for Physical Argument is not argument but conflict. For me Argument is when to people, sides, entities put forward differing views and continue to support, develop and advance them during the course of discussions which do not necessarily have to take place at one time, in one place or even with all protagonists present. For example academic argument.
The physical coming together of bodies whether in conflict or othewise does not, I suggest constitute argument as there is no expression, development or support of views. If there are words spoken before during or after the conflict, that is the argument.
Again emotional argument tends not to be true argument as shouting rude words at each other is not advancing any point of view but merely expressing emotion.
As far as I am concerned I don't think that we are regressing in this respect. People have always shouted rude words at each other and the art of true argument is beyond a lot of people but then it always has been.